Apparatus and method for repairing liquid crystal display device

ABSTRACT

The present invention relates to an apparatus and method for repairing a liquid crystal display panel, which is capable of improving a yield thereof by darkening a bright point to minimize a defect ratio thereof. An apparatus for repairing a liquid crystal display panel according to the present invention includes: a liquid crystal display panel including a repair film formed on any one of a first substrate and a second substrate, which are facing to each other with a liquid crystal layer therebetween; and a laser irradiating device to irradiate a laser to the repair film to darken a specific area of the repair film, which is corresponded to an area where a bright point appears in the liquid crystal display panel.

This application is a Divisional Application of U.S. patent applicationSer. No. 11/289,449, filed Nov. 30, 2005, now U.S. Pat. No. 7,636,148now allowed, which claims the benefit of Korean Patent Application Nos.P2004-105889, P2004-105891, and P2004-105892, filed on Dec. 14, 2004,all of which are hereby incorporated by reference for all purposes as iffully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and method for repairing aliquid crystal display panel, and more particularly, to an apparatus andmethod for repairing a liquid crystal display panel, which is capable ofimproving a yield thereof by darkening a bright point to minimize adefect ratio thereof.

2. Discussion of the Related Art

Generally, a liquid crystal display (LCD) device controls the lighttransmittance of a liquid crystal material in accordance with a videosignal to display a picture. For this, the liquid crystal display deviceincludes a liquid crystal display panel in which liquid crystal cellsare arranged in a matrix configuration, and a drive circuit to drive theliquid crystal display panel.

The liquid crystal display device is divided into two main classes of atwisted nematic (TN) mode in which a vertical direction electric fieldis used and an in-plane switch (ISP) mode in which a horizontaldirection electric field is used, in accordance with the electric fielddirection in which a liquid crystal material is driven.

In the TN mode the liquid crystal material is driven by a verticalelectric field between a pixel electrode and a common electrode that arearranged to be opposite to each other on a lower substrate and an uppersubstrate respectively. The TN mode has an advantage in that itsaperture ratio is big, but a disadvantage in that its viewing angle issmall. In the IPS mode the liquid crystal material is driven by ahorizontal electric field between the pixel electrode and the commonelectrode that are arranged in parallel in a lower substrate. The IPSmode has an advantage in that its viewing angle is big, but adisadvantage in that its aperture ratio is small.

FIG. 1 is a sectional view illustrating a liquid crystal display panelof TN mode of the related art.

Referring to FIG. 1, the related art TN mode liquid crystal displaypanel includes an upper array substrate (or a color filter arraysubstrate) having a black matrix 4, a color filter 6, a common electrode18, and an upper alignment film 8 that are sequentially formed on anupper substrate 2; a lower array substrate having a thin film transistor(hereinafter, referred to as “TFT”), a pixel electrode 16 and a loweralignment film 38 that are formed on a lower substrate 32; and a liquidcrystal material 52 injected into an inner space between the upper arraysubstrate and the lower array substrate.

On the other hand, the IPS mode liquid crystal display panel has thecommon electrode 18 formed on the lower substrate 32 and an overcoatlayer (not shown) formed on the color filter 6 of the upper substrate 2,wherein the overcoat layer is for compensating the stepped difference ofthe color filter 6.

On the upper array substrate of the IPS mode liquid crystal displaypanel, the black matrix 4 is formed on the upper substrate 2 andcorresponds to an area of gate lines and data lines (not shown) and aTFT area of the lower array substrate. The black matrix provides a cellarea where a color filter 6 is to be formed. The black matrix 4 preventslight leakage and absorbs external light, thereby increasing contrast.The color filter 6 is formed to extend to the black matrix 4 and thecell area divided by the black matrix 4. The color filter 6 is formed byRed, Green and Blue to realize R, G and B colors. A common voltage issupplied to the common electrode 18 to control the movement of theliquid crystal material. A pattern spacer 13 maintains a cell gapbetween the upper array substrate and the lower array substrate.

The TFT on the lower array substrate includes a gate electrode 9 formedon the lower substrate 32 along with a gate line; semiconductor layers14, 42 overlapping the gate electrode 9 with a gate insulating film 44therebetween; and source/drain electrodes 40, 47 formed together with adata line (not shown) with the semiconductor layers 14, 42 therebetween.The TFT supplies a pixel signal to a pixel electrode 16 from the dataline in response to a scan signal from the gate line. The pixelelectrode 16 is in contact with the drain electrode 47 of the TFT with apassivation film 50 therebetween, wherein the passivation film 50 isformed of a transparent conductive material with high lighttransmittance. The upper and the lower alignment films 8 and 38 foraligning the liquid crystal material are formed by applying an alignmentmaterial such as polyimide and performing a rubbing process.

If a defect is generated at each thin film of the upper array substrateand the lower array substrate of the related art liquid crystal displaypanel, a repair is performed by rework or using a laser. However, if aparticle is soundly settled between the thin films of both the upperarray substrate and the lower array substrate, it becomes impossible todo the repair by rework or laser.

FIG. 2 is a sectional view for explaining an alignment defect caused byairborne particles, and FIG. 3 is a photo representing a bright pointcaused by the particle upon realizing a picture.

Generally, in processes of manufacturing a liquid crystal display panel,it is possible for particles to settle between their films. For example,particles may settle on the panel in the chamber within which adesignated thin film is formed, or if the panel is moved to a separatechamber or a third location to form another thin film, while the panelis being moved. An example of a particle 55 between the common electrode18 and the upper alignment film 8 is illustrated in FIG. 2. In thisexample the alignment film corresponding to the particle 55 is notuniformly rubbed in a rubbing process, thereby generating a non-uniformalignment area A. Further, a portion of the color filter is separated bya defect on the process upon forming the color filter. Such particles 55intermixed between layers may occur frequently causing various problemsin the LCD panel.

For example, the non-uniform alignment area A causes light leakage inthe liquid crystal display panel, and such light leakage interferes withlight transmittance of the liquid crystal material. The light leakageappears as a bright point in the liquid crystal display panel, asillustrated in FIG. 3. Generally, a dark point is an area appearing darkin case of realizing a high gray, and a bright point is an areaappearing bright in case of realizing a low gray. Herein, human eyes aremore sensitive to a bright point than a dark point, thus a stricterstandard is provided for a bright point defect than a dark point defectwhen determining if a panel is good or bad. Accordingly, a method isrequired to minimize a defect rate of a panel caused by a generation ofa bright point.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an apparatus andmethod for repairing a liquid crystal display panel, which is capable ofimproving a yield thereof by darkening a bright point to minimize adefect ratio thereof.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings. Toachieve these and other advantages and in accordance with the purpose ofthe present invention, as embodied and broadly described, an apparatusfor repairing a liquid crystal display device includes a repair filmformed on any one of a first substrate and a second substrate; and alaser irradiating device to irradiate a laser to the repair film todarken a defect point in the liquid crystal display panel.

The repair film is a transparent organic film.

The repair film is a black matrix formed on the first substrate.

The repair film is a spacer formed between the first and the secondsubstrates and including an opaque material.

The apparatus further comprising a thin film transistor and a pixelelectrode connected to the thin film transistor on the second substrate.

The apparatus further comprising a common electrode formed on the secondsubstrate with the pixel electrode.

The apparatus further comprising a common electrode formed on the firstsubstrate.

In another aspect of the present invention, an apparatus for repairing aliquid crystal display device includes a transparent organic film formedon any one of a first substrate and a second substrate to react tolight; and a laser irradiating device to irradiate a laser to thetransparent organic film to darken a specific area of the transparentorganic film in the liquid crystal display panel.

The transparent organic film contains a photo active compound.

The transparent organic film comprises any one of a novolac systemorganic material with a photo active compound and an acryl systemorganic material with the photo active compound.

The apparatus further comprising a focus controller located between theliquid crystal display panel and the laser irradiating device to adjustan irradiation area of the laser and a focus distance.

The focus controller includes at least one of a lens and a mirror.

In another aspect of the present invention, an apparatus for repairing aliquid crystal display device, comprising: a first substrate having ablack matrix and a second substrate facing to the first substrate with aliquid crystal layer therebetween; and a laser irradiating device toirradiate a laser to the black matrix near to a defect area in theliquid crystal display panel to extend the black matrix to the defectarea.

The black matrix includes a polyimide mixed with a pigment of carbonsystem.

The laser irradiating device irradiates the laser to the black matrixand moves the laser to the defect area.

In another aspect of the present invention, an apparatus for repairing aliquid crystal display device includes a first substrate and a secondsubstrate and a spacer formed between the first and the secondsubstrates and including an opaque material; and a laser irradiatingdevice to irradiate a laser to the spacer near to a defect area in theliquid crystal display panel to extend the spacer to the defect area.

The opaque material includes an acryl system material with at least oneof a carbon and a metallic oxide.

The laser irradiating device irradiates the laser to the spacer andmoves the laser to the defect area.

The spacer includes at least one of a pattern spacer and a ball spacer.

In another aspect of the present invention, a method for repairing aliquid crystal display device includes forming a transparent organicfilm on any one of a first substrate and a second substrate; sensing adefect area in the liquid crystal display panel; and irradiating a laserto an area of the transparent organic film corresponding to the defectarea.

The method further comprising adjusting an irradiation area of the laserand a focus distance by using a focus controller.

In another aspect of the present invention, a method for repairing aliquid crystal display device includes forming a black matrix on asubstrate; sensing a defect area in the liquid crystal display panel;and irradiating a laser to the black matrix near to the defect area.

Irradiating a laser to the black matrix near to the defect includesirradiating the laser to the black matrix; and moving the laser to thedefect area.

In another aspect of the present invention, A method for repairing aliquid crystal display device includes forming a spacer between a firstand a second substrates and including an opaque material; sensing andefect area in the liquid crystal display panel; irradiating a laser tothe spacer near to the defect area.

Irradiating a laser to the spacer near to the defect area includes:irradiating the laser to the spacer; and moving the laser to the defectarea.

In yet another aspect of the present invention, a liquid crystal displaydevice includes a transparent organic film formed on any one of a firstsubstrate and a second substrate; wherein the transparent organic filmincludes at least one darkened area.

In yet another aspect of the present invention, a liquid crystal displaydevice includes a black matrix on a substrate, wherein the black matrixincludes at least one extended area corresponded to a defect area.

In yet another aspect of the present invention, a liquid crystal displaydevice includes a spacer formed between a first substrate and a secondsubstrates and including an opaque material; wherein the spacer includesat least one extended area corresponded to a defect area.

In yet another aspect of the present invention, a liquid crystal displaydevice includes a repair film formed on any one of a first substrate anda second substrate; wherein the repair film has at least one of adarkened area corresponding a defect area.

The device further comprising a first and second substrate; and a thinfilm transistor and a pixel electrode connected to the thin filmtransistor on the second substrate.

The device further comprising a common electrode formed on the secondsubstrate with the pixel electrode.

The device further comprising a common electrode formed on the firstsubstrate.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a sectional view illustrating a related art liquid crystaldisplay panel;

FIG. 2 is a sectional view for explaining an alignment defect caused byan airborne particle;

FIG. 3 is a photo representing a bright point caused by the particleupon realizing a picture.

FIG. 4 is a sectional view illustrating an apparatus for repairing aliquid crystal display panel according to a first embodiment of thepresent invention;

FIG. 5 is a sectional view illustrating a method of repairing the liquidcrystal display panel according to the first embodiment of the presentinvention;

FIG. 6 is a flow chart for explaining the method of repairing the liquidcrystal display panel according to the first embodiment of the presentinvention;

FIG. 7 is a sectional view illustrating an apparatus for repairing aliquid crystal display panel according to a second embodiment of thepresent invention;

FIG. 8 is a sectional view illustrating a method of repairing the liquidcrystal display panel according to the second embodiment of the presentinvention;

FIG. 9 is a flow chart for explaining the method of repairing the liquidcrystal display panel according to the second embodiment of the presentinvention;

FIG. 10 is a sectional view illustrating an apparatus for repairing aliquid crystal display panel according to a third embodiment of thepresent invention;

FIG. 11 is a sectional view illustrating a method of repairing theliquid crystal display panel according to the third embodiment of thepresent invention; and

FIG. 12 is a flow chart for explaining the method of repairing theliquid crystal display panel according to the third embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings.

Hereinafter, the embodiments of the present invention will be describedin detail with reference to FIGS. 4 to 12.

FIG. 4 is a sectional view illustrating an apparatus for repairing aliquid crystal display panel according to a first embodiment of thepresent invention.

Referring to FIG. 4, an apparatus for repairing a liquid crystal displaypanel according to the first embodiment of the present inventionincludes a liquid crystal display panel 170 having a repair film(hereinafter, referred to as “transparent organic film”) 120. Thetransparent organic film 120 may be used to darken an area where thereis a bright point on the liquid crystal display panel 170 caused by analignment defect resulting from a particle 155 intermixed in the liquidcrystal display panel 170. The apparatus further includes a laserirradiating device 160 to irradiate a laser to the transparent organicfilm 120 to darken the transparent organic film 120 in an areacorresponding to a bright point.

The liquid crystal display panel 170 includes an upper array substrate(or a color filter array substrate) having a black matrix 104, a colorfilter 106, a common electrode 118, a pattern spacer 113, and an upperalignment film 108 that are sequentially formed on an upper substrate102; a lower array substrate having a thin film transistor (hereinafter,referred to as “TFT”), a pixel electrode 116 and a lower alignment film138 that are formed on a lower substrate 132; and a liquid crystalmaterial 152 in a space between the upper array substrate and the lowerarray substrate.

The transparent organic film 120 is coated on an entire surface of theupper substrate 102 so that it substantially covers the upper substrate102. The black matrix 104 is formed in an area corresponding to an areaof gate lines and data lines (not shown) and a TFT area of the lowerarray substrate, and it defines a cell area where a color filter 106 isto be formed. The black matrix 104 may be formed of polyimide, in whicha pigment of carbon system is mixed, to prevent light leakage and toabsorb external light, thereby increasing contrast. The color filter 106extends to the black matrix 104 and the cell area divided by the blackmatrix 104. The color filter 106 includes Red, Green and Blue to realizeR, G and B colors. A common voltage is supplied to the common electrode118 to control the movement of the liquid crystal material. The patternspacer 113 maintains a cell gap between the upper array substrate andthe lower array substrate.

The transparent organic film 120 according to the present invention isformed by adding a photo active compound to any one of a novolac systemorganic material and an acryl system organic material, so that darkeningby a laser can be possible.

The TFT includes a gate electrode 109 formed on the lower substrate 132along with a gate line; semiconductor layers 114, 147 overlapping thegate electrode 109 with a gate insulating film 144 therebetween; andsource/drain electrodes 140, 142 formed together with a data line (notshown) with the semiconductor layers 114, 147 therebetween. The TFTsupplies a pixel signal to a pixel electrode 116 from the data line inresponse to a scan signal from the gate line.

The pixel electrode 116 is in contact with a drain electrode 142 of theTFT with a passivation film 150 therebetween, wherein the pixelelectrode 116 is formed of a transparent conductive material with highlight transmittance. The upper and the lower alignment films 108 and 138for aligning the liquid crystal material are formed by applying analignment material such as polyimide and performing a rubbing process.On the other hand, the IPS mode liquid crystal display panel has thecommon electrode 118 formed on the lower substrate 132 and an overcoatlayer (not shown) formed on the color filter 106 of the upper substrate102, wherein the overcoat layer is for compensating the step differenceof the color filter 106.

The laser irradiating device 160 irradiates a laser to the transparentorganic film 120 in an area corresponding to a bright point in theliquid crystal display panel 170 caused by an alignment defect, such asa particle 155 trapped after combining the upper array substrate to thelower array substrate. For instance, as illustrated in FIG. 5, whenthere is a bright point in the liquid crystal display panel 170, thelaser irradiating device 160 irradiates a laser to the transparentorganic film in an area corresponding to the bright point.

Herein, the laser irradiating device 160 may further include a focuscontroller 162. The laser can be accurately adjusted to an irradiationarea using the focus controller 162 located between the laserirradiating device 10 and the liquid crystal display panel 170.

In this case, the laser of the laser irradiating device 160 isirradiated to the transparent organic film 120 with a strong energy ofabout 0.1 J/cm² to 2 J/cm². And, the transparent organic film 120, towhich the photo active compound has been added, reacts to light, so thatcharacteristics of the transparent organic film 120 change and thetransparent organic film 120 darkens or becomes substantially opaque. Asa result, the area of the liquid crystal display panel corresponding tothe particle 155 is darkened.

In this way, a bright point caused by the alignment defect is darkenedto minimize a defect ratio of the liquid crystal display panel.Accordingly, a yield of the liquid crystal display panel is improved.

Herein, the laser irradiating device 160 may be at least one of an Ndyttrium aluminum garnet YAG laser, an eximer laser, and a diode laser.The Nd yttrium aluminum garnet YAG laser is a laser that oscillates byusing a neodymium Nd solid and a YAG crystal as an amplification medium.In the eximer laser a molecule in an excitation state (that is, aneximer made from both an excitation state and an atom of a ground state)generates light and then enters a dissociation state. The diode laser isa laser that oscillates using the light generated upon the energy levelchange or the carrier movement of the joining part of an n-typesemiconductor and a p-type semiconductor.

The Nd YAG laser has wavelengths of about 330 nm˜340 nm, about 530nm˜540 nm, and about 1060 nm˜1070 nm; the eximer laser has a wavelengthof about 190 nm˜200 nm; and the diode laser has a wavelength of about100 nm˜1000 nm.

Further, a laser generated by each of CO, CO₂, He—Ne, and HF may beused. The CO laser has a wavelength of about 4900 nm˜5100 nm, the CO₂laser has a wavelength of about 100 nm˜110 nm, the He—Ne laser has awavelength of about 630 nm˜640 nm, and the HF laser has a wavelength ofabout 2700 nm˜2900 nm.

As described above, in the apparatus of repairing the liquid crystaldisplay panel according to the first embodiment of the presentinvention, the laser is irradiated to the transparent organic film 120in the area corresponding to the area where the bright point is causedby an alignment defect to darken the area where the bright point isgenerated. Thus, light radiated from a backlight does not pass throughthe LCD panel where the defect occurs. As a result, it is possible toreduce generation of a bright point. Accordingly, it is possible tominimize a defect ratio of the liquid crystal display panel and toimprove a yield of the liquid crystal display panel.

In the description according to the first embodiment of the presentinvention, the transparent organic film 120 is formed on the uppersubstrate 102, but the transparent organic film 120 may be formed on thelower substrate 132 instead of or in addition to the transparent organicfilm on the upper substrate. Because a case that the transparent organicfilm 120 is formed on the lower substrate 132 is substantially the sameas the case that the transparent organic film 120 is formed on the uppersubstrate 102, a description of the transparent organic film 120 on thelower substrate 132 will be omitted.

FIG. 6 is a flow chart for explaining the method of repairing the liquidcrystal display panel according to the first embodiment of the presentinvention.

Referring to FIG. 6, the upper array substrate (or, a color filter arraysubstrate) having the black matrix 104, the color filter 106, the commonelectrode 118, the pattern spacer 113 and the upper alignment film 108,which are sequentially formed on the upper substrate 102, is formed(S2).

Further, the lower array substrate having the gate line and the dataline, the thin film transistor which is formed at the crossing of thegate line and the data line, the pixel electrode 116 connected to thethin film transistor, and the lower alignment film 138, which are formedon the lower substrate 132, is formed by a separate process (S4). On theother hand, in case of the liquid crystal display panel of IPS mode, thecommon electrode 118 is formed on the lower substrate 132 and anovercoat layer is formed on the color filter 106 of the upper substrate102.

After this, the upper substrate and the lower substrate are bondedtogether and the liquid crystal is provided therebetween to form theliquid crystal display panel (S6).

Thereafter, when the particle 155 inserted between a thin film and athin film of the upper substrate, e.g., between the common electrode 118and the upper alignment film 108, causes a bright point, the laser isirradiated to the transparent organic film 120 in an area correspondingto the bright point to make the transparent organic film 120 of thatcorresponding area substantially opaque. Accordingly, the bright pointis essentially darkened (S8).

In this case, the transparent organic film is formed by adding a photoactive compound to any one of a novolac system organic material and anacryl system organic material, so that darkening by a laser can bepossible.

Accordingly, the bright point caused by an alignment defect is darkenedto minimize a defect ratio of the liquid crystal display panel. Thus, itis possible improve a yield of the liquid crystal display panel.

In this way, the method in which the laser is irradiated to thetransparent organic film 120 to darken the area where the bright pointis generated can be easily applied to the liquid crystal display panelof electrical controlled birefringence (ECB), further vertical alignment(VA) mode, as well as to the liquid crystal display panel of IPS modeand the liquid crystal display panel of TN mode.

FIG. 7 is a sectional view illustrating an apparatus for repairing aliquid crystal display panel according to a second embodiment of thepresent invention.

Referring to FIG. 7, an apparatus for repairing a liquid crystal displaypanel according to the second embodiment of the present inventionincludes a laser irradiating device 260, which irradiates a laser to ablack matrix 204 of an area near to the area where a bright point isgenerated to darken the area where a particle 255 is intermixed.

The liquid crystal display panel 270 includes an upper array substrate(or a color filter array substrate) having a black matrix 204, a colorfilter 206, a common electrode 218, a pattern spacer 213, and an upperalignment film 208 that are sequentially formed on an upper substrate202; a lower array substrate having a thin film transistor (hereinafter,referred to as “TFT”), a pixel electrode 216 and a lower alignment film238 that are formed on a lower substrate 232; and a liquid crystalmaterial 252 in a space between the upper array substrate and the lowerarray substrate.

In the upper array substrate, the black matrix 204 is formed on theupper substrate 202 in an area corresponding to an area of gate linesand data lines (not shown) and the TFT area of the lower arraysubstrate. The black matrix provides a cell area where a color filter206 is to be formed. The black matrix 204 may be formed of polyimide, inwhich a pigment of carbon system is mixed, to prevent light leakage andto absorb external light, thereby acting to increase contrast. The colorfilter 206 extends to the black matrix 204 and the cell area divided bythe black matrix 204. The color filter 206 is formed by Red, Green andBlue to realize R, G and B colors. A common voltage is supplied to thecommon electrode 218 to control the movement of the liquid crystalmaterial. The pattern spacer 213 maintains a cell gap between the upperarray substrate and the lower array substrate.

On the lower array substrate, the TFT includes a gate electrode 209formed on the lower substrate 232 along with a gate line; semiconductorlayers 214, 247 overlapping the gate electrode 209 with a gateinsulating film 244 therebetween; and source/drain electrodes 240, 242formed together with a data line (not shown) with the semiconductorlayers 214, 247 therebetween. The TFT supplies a pixel signal to a pixelelectrode 216 from the data line in response to a scan signal from thegate line.

The pixel electrode 216 is in contact with a drain electrode 242 of theTFT with a passivation film 250 therebetween, wherein the passivationfilm 250 is formed of a transparent conductive material with high lighttransmittance. The upper and the lower alignment films 208 and 238 foraligning the liquid crystal material are formed by applying an alignmentmaterial such as polyimide and performing a rubbing process. On theother hand, the IPS mode liquid crystal display panel has the commonelectrode 218 formed on the lower substrate 232 and an overcoat layer(not shown) formed on the color filter 206 of the upper substrate 202,wherein the overcoat layer is for compensating the step difference ofthe color filter 206.

The laser irradiating device 260 irradiates a laser to the black matrixnear to an area where there is a bright point generated in the liquidcrystal display panel 270 by an alignment defect such as a particle 255trapped after combining the upper array substrate to the lower arraysubstrate. For instance, as illustrated in FIG. 8, when there is abright point in the liquid crystal display panel 270, the laserirradiating device 260 irradiates a laser to the black matrix 204 nearto the area of the bright point.

The laser of the laser irradiating device 260 is irradiated to the blackmatrix 204 with a strong energy of about 0.1 J/cm² to 2 J/cm².Accordingly, characteristics of the black matrix 204 are changed due tothe strong energy, so that the black matrix 204 becomes moveable. Inother words, the black matrix 204 is melted by the strong energy. And atthis time, if the laser is moved from the black matrix 204 to the areawhere the bright point is generated, then the melted black matrix 204moves to the area where the bright point is generated. Accordingly, thearea of the bright point is darkened.

In this way, the bright point caused by the alignment defect is darkenedto minimize a defect ratio of the liquid crystal display panel.Accordingly, a yield of the liquid crystal display panel is improved.

Herein, the laser irradiating device 160 may be at least one of an Ndyttrium aluminum garnet YAG laser, an eximer laser, and a diode laser.The Nd yttrium aluminum garnet YAG laser is a laser that oscillates byusing a neodymium Nd solid and a YAG crystal as an amplification medium.In the eximer laser a molecule in an excitation state (that is, aneximer made from both an excitation state and an atom of a ground state)generates light and then enters a dissociation state. The diode laser isa laser that oscillates using the light generated upon the energy levelchange or the carrier movement of the joining part of an n-typesemiconductor and a p-type semiconductor.

The Nd YAG laser has wavelengths of about 330 nm˜340 nm, about 530nm˜540 nm, and about 1060 nm˜1070 nm; the eximer laser has a wavelengthof about 190 nm˜200 nm; and the diode laser has a wavelength of about100 nm˜1000 nm.

Further, a laser generated by each of CO, CO₂, He—Ne, and HF may beused. The CO laser has a wavelength of about 4900 nm˜5100 nm, the CO₂laser has a wavelength of about 100 nm˜110 nm, the He—Ne laser has awavelength of about 630 nm˜640 nm, and the HF laser has a wavelength ofabout 2700 nm˜2900 nm.

As described above, in the apparatus for repairing the liquid crystaldisplay panel according to the second embodiment of the presentinvention, the laser is irradiated to the black matrix 204 in the areanear to where there is a bright point in the liquid crystal displaypanel 270 caused by an alignment defect such as the particle 255 todarken the area corresponding to the bright point. Thus, the blackmatrix 204 is extended to the area where there is a bright point todarken the bright point. As a result, light radiated from a backlightdoes not pass through the LCD panel where the defect occurs.Accordingly, it is possible to reduce a generation of a bright point.Thus, it is possible to minimize a defect ratio of the liquid crystaldisplay panel and to improve a yield of the liquid crystal displaypanel.

FIG. 9 is a flow chart for explaining the method of repairing the liquidcrystal display panel according to the second embodiment of the presentinvention.

Referring to FIG. 9, the upper array substrate (or, a color filter arraysubstrate) having the black matrix 204, the color filter 206, the commonelectrode 218, the pattern spacer 213 and the upper alignment film 208,which are sequentially formed on the upper substrate 202, is formed(S12).

Further, the lower array substrate having the gate line and the dataline, the thin film transistor that is formed at the crossing of thegate line and the data line, the pixel electrode 216 connected to thethin film transistor, and the lower alignment film 238, which are formedon the lower substrate 232, is formed by a separate process (S14). Onthe other hand, in case of the liquid crystal display panel of IPS mode,the common electrode 218 is formed on the lower substrate 232 and anovercoat layer is formed on the color filter 206 of the upper substrate202.

After this, the upper substrate and the lower substrate are bondedtogether and the liquid crystal is provided therebetween to form theliquid crystal display panel (S16).

Thereafter, when the particle 255 inserted between a thin film and athin film of the upper substrate, e.g., between the common electrode 218and the upper alignment film 208, causes a bright point, the laser isirradiated to the black matrix 204 of the area near to the area wherethe bright point is generated to melt the block matrix 204. In thiscase, the laser irradiating device 260 scans its laser in order to movethe black matrix 204, which is melted to the area where the bright pointis generated. Accordingly, the bright point is darkened (S18).

The black matrix 204 may be formed of polyimide, in which a pigment ofcarbon system is mixed, and extends to the bright point to interceptlight irradiated from the back light. Thus, the bright point isdarkened. As a result, the bright point caused by an alignment defect isdarkened to minimize a defect ratio of the liquid crystal display panel.Accordingly, it is possible improve a yield of the liquid crystaldisplay panel.

In this way, the method, in which the laser is irradiated to the blackmatrix 204 to darken the area where the bright point is generated can beeasily applied to the liquid crystal display panel of electricalcontrolled birefringence (ECB), further vertical alignment (VA) mode, aswell as to the liquid crystal display panel of IPS mode and the liquidcrystal display panel of TN mode.

FIG. 10 is a sectional view illustrating an apparatus for repairing aliquid crystal display panel according to a third embodiment of thepresent invention.

Referring to FIG. 10, an apparatus for repairing a liquid crystaldisplay panel according to the third embodiment of the present inventionincludes a laser irradiating device 360, which irradiates a laser to apattern spacer 313 of an area near to the area where a bright point isgenerated to darken the area where a particle 355 is intermixed.

The liquid crystal display panel 370 includes an upper array substrate(or a color filter array substrate) having a black matrix 304, a colorfilter 306, a common electrode 318, a pattern spacer 313, and an upperalignment film 308 which are sequentially formed on an upper substrate302; a lower array substrate having a thin film transistor (hereinafter,referred to as “TFT”), a pixel electrode 316 and a lower alignment film338 which are formed on a lower substrate 332; and a liquid crystalmaterial 352 in a space between the upper array substrate and the lowerarray substrate.

On the upper array substrate, the black matrix 304 is formed on theupper substrate 302 in an area corresponding to an area corresponding toan area of gate lines and data lines (not shown) and the TFT area of thelower array substrate. The black matrix provides a cell area where acolor filter 306 is to be formed. The black matrix 304 prevents lightleakage and absorbs external light, thereby increasing contrast. Thecolor filter 306 extends to the black matrix 304 and the cell areadivided by the black matrix 304. The color filter 306 is formed by Red,Greed and Blue to realize R, G and B colors. A common voltage issupplied to the common electrode 318 to control the movement of theliquid crystal material. The pattern spacer 313 acts to keep a cell gapbetween the upper array substrate and the lower array substrate.

Herein, the pattern spacer 313 of the present invention is formed of anopaque material, which is formed by adding any one of carbon andmetallic oxide to an acryl system material.

In the lower array substrate, the TFT includes a gate electrode 309formed on the lower substrate 332 along with a gate line; semiconductorlayers 314, 347 overlapping the gate electrode 309 with a gateinsulating film 344 therebetween; and source/drain electrodes 340, 342formed together with a data line (not shown) with the semiconductorlayers 314, 347 therebetween. The TFT supplies a pixel signal to a pixelelectrode 316 from the data line in response to a scan signal from thegate line.

The pixel electrode 316 is in contact with a drain electrode 342 of theTFT with a passivation film 350 therebetween, wherein the passivationfilm 350 is formed of a transparent conductive material with high lighttransmittance. The upper and the lower alignment films 308 and 338 foraligning the liquid crystal material are formed by applying an alignmentmaterial such as polyimide and performing a rubbing process. On theother hand, the IPS mode liquid crystal display panel has the commonelectrode 318 formed on the lower substrate 332 and an overcoat layer(not shown) formed on the color filter 306 of the upper substrate 302,wherein the overcoat layer is for compensating the step difference ofthe color filter 306.

The laser irradiating device 360 irradiates a laser to the patternspacer 313 near to an area where there is a bright point in the liquidcrystal display panel 370 caused by an alignment defect such as theparticle 355 trapped after combining the upper array substrate to thelower array substrate. For instance, as illustrated in FIG. 11, whenthere is a bright point in the liquid crystal display panel 370, thelaser irradiating device 360 irradiates a laser to the pattern spacer313 near to the area of the bright point.

The laser of the laser irradiating device 360 is irradiated to thepattern spacer 313 with a strong energy of about 0.1 J/cm² to 2 J/cm².Accordingly, characteristics of the pattern spacer 313 change due to thestrong energy, so that the pattern spacer 313 becomes moveable. In otherwords, the pattern spacer 313 is melted by the strong energy. And atthis time, if the laser is moved from the pattern spacer 313 to the areawhere the bright point is generated, then the melted pattern spacer 313moves to the area, where the bright point is generated. Accordingly, thebright point is darkened.

In this way, the bright point caused by the alignment defect is darkenedto minimize a defect ratio of the liquid crystal display panel.Accordingly, a yield of the liquid crystal display panel is improved.

Herein, the laser irradiating device 160 may be at least one of an Ndyttrium aluminum garnet YAG laser, an eximer laser, and a diode laser.The Nd yttrium aluminum garnet YAG laser is a laser that oscillates byusing a neodymium Nd solid and a YAG crystal as an amplification medium.In the eximer laser a molecule in an excitation state (that is, aneximer made from both an excitation state and an atom of a ground state)generates light and then enters a dissociation state. The diode laser isa laser that oscillates using the light generated upon the energy levelchange or the carrier movement of the joining part of an n-typesemiconductor and a p-type semiconductor.

The Nd YAG laser has wavelengths of about 330 nm˜340 nm, about 530nm˜540 nm, and about 1060 nm˜1070 nm, the eximer laser has a wavelengthof about 190 nm˜200 nm, and the diode laser has a wavelength of about100 nm-1000 nm.

Further, a laser generated by each of CO, CO₂, He—Ne, and HF may beused. The CO laser has a wavelength of about 4900 nm˜5100 nm, the CO₂laser has a wavelength of about 100 nm˜110 nm, the He—Ne laser has awavelength of about 630 nm˜640 nm, and the HF laser has a wavelength ofabout 2700 nm˜2900 nm.

As described above, in the apparatus of repairing the liquid crystaldisplay panel according to the third embodiment of the presentinvention, the laser is irradiated to the pattern spacer 313 in the areanear to the area where there is a bright point in the liquid crystaldisplay panel 370 caused by an alignment defect such as the particle 355to darken the area corresponding to the bright point. Thus, the patternspacer 313 is extended to the area where there is a bright point todarken the bright point. As a result, light radiated from a backlightdoes not pass through the LCD panel where the defect occurs.Accordingly, it is possible to reduce a generation of a bright point.Thus, it is possible to minimize a defect ratio of the liquid crystaldisplay panel and to improve a yield of the liquid crystal displaypanel.

In the description referring to FIG. 11, only case of the pattern spacer313 is described, but the principles of the present invention also applywhen a ball spacer is used.

FIG. 12 is a flow chart for explaining the method of repairing theliquid crystal display panel according to the third embodiment of thepresent invention.

Referring to FIG. 12, the upper array substrate (or, a color filterarray substrate) having the black matrix 304, the color filter 306, thecommon electrode 318, the pattern spacer 313 and the upper alignmentfilm 308, which are sequentially formed on the upper substrate 302, isformed (S22).

Further, the lower array substrate having the gate line and the dataline, the thin film transistor which is formed at the crossing of thegate line and the data line, the pixel electrode 316 connected to thethin film transistor, and the lower alignment film 338, which are formedon the lower substrate 332, is formed by a separate process (S24). Onthe other hand, in case of the liquid crystal display panel of IPS mode,the common electrode 318 is formed on the lower substrate 332 and anovercoat layer is formed on the color filter 306 of the upper substrate302.

After this, the upper substrate and the lower substrate are bondedtogether and the liquid crystal is provided therebetween to form theliquid crystal display panel (S26).

Thereafter, when the particle 355 inserted between a thin film and athin film of the upper substrate, e.g., between the common electrode 318and the upper alignment film 308, causes a bright point, the laser isirradiated to the pattern spacer 313 of the area near to the area wherethe bright point is generated to melt the pattern spacer 313. In thiscase, the laser irradiating device 360 scans its laser in order to movethe pattern spacer 313, which is melted to the area where the brightpoint is generated. Accordingly, the bright point is darkened (S28).

The pattern spacer 313 may be formed of acryl system material, to whichany one of carbon and metallic oxide is added, and extends to the brightpoint to intercept light irradiated from the back light. Thus, thebright point is darkened. As a result, the bright point caused by analignment defect is darkened to minimize a defect ratio of the liquidcrystal display panel. Accordingly, it is possible improve a yield ofthe liquid crystal display panel.

In this way, the method, in which the laser is irradiated to the patternspacer 313 to darken the area where the bright point is generated, canbe easily applied to the liquid crystal display panel of electricalcontrolled birefringence (ECB), further vertical alignment (VA) mode, aswell as to the liquid crystal display panel of IPS mode and the liquidcrystal display panel of TN mode.

As described above, in the apparatus and the method for repairing theliquid crystal display panel according to the embodiment of the presentinvention, the transparent organic film is formed on any one of theupper substrate and the lower substrate in a case that a bright point isgenerated in the liquid crystal display panel due to a problem inmanufacturing the liquid crystal display panel. A laser is irradiated tothe transparent organic film where the bright point is generated tothereby make the transparent organic film substantially opaque. As aresult, the area where the bright point is generated is darkened.Accordingly, the bright point of the liquid crystal display panel isdarkened to minimize a defect ratio of the liquid crystal display panel.Thus, it is possible to improve a yield of the liquid crystal displaypanel.

Further, in the case that the bright point is generated, the laser maybe irradiated to the black matrix in the area near to the particle tomelt the black matrix so that the melted black matrix is extended to thearea where the bright point is generated to thereby darken the area.Accordingly, the bright point is darkened to minimize a defect ratio ofthe liquid crystal display panel. Thus, it is possible to improve ayield of the liquid crystal display panel.

Moreover, in the case that the bright point is generated, the laser maybe irradiated to the pattern spacer in the area near to the particle tomelt the pattern spacer so that the melted pattern spacer is extended tothe area where the bright point is generated to thereby darken the area.Accordingly, the bright point is darkened to minimize a defect ratio ofthe liquid crystal display panel. Thus, it is possible to improve ayield of the liquid crystal display panel.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A liquid crystal display device, comprising:first and second substrates; a plurality of thin films on each of thefirst and second substrates; a black matrix on one of the first andsecond substrates that defines pixel areas for displaying an image;wherein the black matrix is extended to cover a defective area of atleast one pixel to block light transmission.
 2. A liquid crystal displaydevice, comprising: a first substrate and a second substrate; a dataline and a gate line on the first substrate, the data line and the gatelines crossing each other; a thin film transistor at a crossing of thedata and gate lines; a pixel electrode on the first substrate; a commonelectrode on one of the first and second substrates; a liquid crystallayer between the first and second substrates; and a repair film on oneof the first and second substrates, wherein a physical characteristic ofthe repair film is alterable by the application of a laser to blocklight transmitted through a portion of the first substrate correspondingto a defect, and wherein the repair film is a black matrix, and whereinthe repair film includes a portion extended to correspond to a regionhaving a defect, the extended portion including material melted from theblack matrix.
 3. The device according to claim 1, further comprising acolor filter layer formed on the black matrix.
 4. The device accordingto claim 3, further comprising an overcoat layer formed on the colorfilter layer.
 5. The device according to claim 1, wherein the blackmatrix includes a polyimide mixed with a pigment of carbon system. 6.The device according to claim 1, wherein the extended portion of theblack matrix blocks light transmission through a bright point defect inthe at least one pixel area.
 7. The device according to claim 6, furthercomprising an alignment layer formed on one of the first and secondsubstrates, and wherein the bright point defect includes a misalignedregion of the alignment layer.
 8. The device according to claim 3,wherein the extended portion includes material melted from the blackmatrix.
 9. The device according to claim 3, wherein the extended portionis in the color filter layer within the at least one pixel area.
 10. Thedevice according to claim 1, further comprises: alignment films on thefirst and second substrates to align liquid crystal molecules, at leastone of the alignment films having an uneven alignment area associatedwith an undesired particle in at least one of the pixel areas, whereinthe black matrix is extended to cover the uneven alignment area to blocklight transmission.